Forecasting Terminology

The most common terms used for weather forecasts, describing the duration, distribution and probability of occurrence of rainfall.

For Duration of Rainfall

• Brief - short, sudden showers or periods of rain

• Intermittent - on and off intervals, not continuous

• Occasional - irregular, infrequent intervals of precipitation

• Frequent - persistent short intervals, happening regularly and often

• Periods of precipitation - rain or snow falling most of the time with breaks

For Distribution of rainfall

• Isolated - showers separated during a given period of time

• Few - indicated in time, not over an area

• Local - restricted to a smaller area

• Patchy - irregularly occurring in an area

• Scattered - not widespread but of greater occurrence than isolated showers

• Widespread – covering wide area, nearly 75%

• Fairly Widespread – covering all area, almost 100%.

For Probability of Occurrence of Rainfall